WRIST ACTIGRAPHIC ASSESSMENT OF SLEEP IN 116 COMMUNITY-BASED SUBJECTSSUSPECTED OF OBSTRUCTIVE SLEEP-APNEA SYNDROME

Background - The combined use of wrist actigraphic assessment and self assessment of sleep in the screening of obstructive sleep apnoea synd rome was evaluated in a community based sample. Methods - One hundred and sixteen community based subjects clinically suspected of having ob structive sleep apnoea (syndrome) were evaluated by means of simultane ous ambulatory recording of respiration (oronasal flow thermistry), mo tor activity (wrist actigraphy), and subjective sleep (sleep log) duri ng one night of sleep. Results - The subjects were distributed accordi ng to their apnoea index (AI); AI<1 (non-apnoeic snorers) 44%; AI 1-<5 39%; and AI greater than or equal to 5 17%. High apnoea index values were associated with self reported disturbed sleep initiation and more fragmented and increased levels of motor activity and decreased durat ion of immobility periods, particularly in those with an apnoea index of greater than or equal to 5. Across subjects the duration of immobil ity periods was the only predictor of the apnoea index, explaining 11% of its variance. Use of the multiple regression equation to discrimin ate retrospectively between those with an apnoea index of <1 and great er than or equal to 5 resulted in sensitivity and specificity values o f 75% and 43%, and 5% and 100%, respectively. Conclusions - The combin ed use of a sleep log and actigraphic assessment of sleep failed to id entify reliably those subjects who suffered from obstructive sleep apn oea (syndrome) in a sample of community based subjects reporting habit ual snoring combined with excessive daytime sleepiness and/or nocturna l respiratory arrests.